The present invention relates to a construction equipment control system used in civil engineering work such as ground leveling, and in particular, to a construction equipment control system utilizing a laser reference plane formed by rotary irradiation a of laser beam in order to control the height in ground leveling operation.
When ground leveling operation is performed for construction work such as development of housing area or road pavement using construction equipment for ground leveling, e.g. grader, bulldozer, etc., it is necessary to have a reference for the height of ground leveling. In recent years, in order to determine such height, which serves as a reference in ground leveling operation, a system using a laser beam has been propagated. As one of such systems using the laser beam, there is a control system for construction equipment provided with a rotary laser irradiating system.
FIG. 6 shows a case where the control system for construction equipment is adopted for a bulldozer.
In FIG. 6, reference numeral 1 represents a rotary laser irradiating system, and 2 a bulldozer, and the rotary laser irradiating system 1 is installed on a tripod 3 at a predetermined position in a housing area under development. The rotary laser irradiating system 1 irradiates the laser beam 4 in a horizontal direction and rotates it and forms a reference plane by the laser beam 4.
The bulldozer 2 has a blade 5, which is supported in such manner that it can be moved up or down, and a pole 6 is erected on the blade 5. A level sensor 7 is mounted on the pole 6. The level sensor 7 receives the laser beam 4 from the rotary laser irradiating system 1 and detects a photodetecting position. The bulldozer 2 is provided with a control device (not shown) which detects the height of the blade 5 based on a photodetection signal from the level sensor 7, and controls the height of the blade 5 based on the result of detection.
As described above, a horizontal reference plane is formed by the laser beam, and it is possible to perform grounding leveling and to form a horizontal surface by keeping a distance between the horizontal reference plane and a blade edge 5a of the blade 5. By varying the distance with respect to the blade edge 5a, it is possible to change the height of the ground surface to be leveled.
Ground leveling is performed not only to level the ground to a horizontal surface. In many cases, it is rather necessary to perform ground leveling to form an inclined surface. In the construction work to develop housing area, it is necessary to maintain a gradient suitable for water drainage. In the work to pave road, it is necessary to keep a gradient suitable for the specific topography and for water drainage. In conventional type construction equipment control system, it has been practiced to perform ground leveling to produce a flat plane at first and then to form an inclined ground surface with a predetermined gradient based on the result of surveying operation.
In this respect, by the conventional type construction equipment control system as described above, it is possible to perform ground leveling and to produce the horizontal ground surface without requiring skill of an experienced operator, while it has been a work difficult to perform and requiring high grade of skill to keep a gradient on the leveled ground surface. The finishing results of the leveling of inclined ground surface depend much on the skill of the operator, and the progress of the work varies according to the skill of each operator, and there are also the problems in the finished ground surface and process control.